Sterile disposable filters are employed in medicine to guard against contamination, particularly as an insert in syringes, intravenous cannulas, probes or infusion means. In the pharmaceutical and microbiology industries such disposable filters have applications in laboratories for the intake or through-flow of liquids, which must be freed of contamination; in such applications the disposable filter is inserted between a syringe body and its associated penetrating needle or cannula.
Such disposable filters are commercially available as Minisart® filters from Sartorius AG of Göttingen, Germany. Such filters generally comprise a sterile filter membrane encapsulated in a filter holder. The filter holder typically is provided with a connection for the syringe body and for the syringe needle, both in the form of female/male Luer Lock® connectors. An infusion line or a syringe needle can be coupled to the needle connection. The disposable filter can be used as a pre-filter for an optional liquid container, which itself can be equipped with a Luer Lock® connector. The syringe body generally has a conically shaped connection piece on its discharge end which is capable of being coupled to the syringe connection of the filter holder. The filter membrane is to prevent contaminating materials, which may be present in the syringe liquid, from migrating into the so-called downstream zone, that is, into the area of the needle or fluid discharge line.
The disposable filter is in a filter package comprising a package housing and a package cover and disposed therein in such a manner that the syringe connection of the disposable filter is proximal to the package cover. The package cover is sealed airtight with the housing by adhesive. The filter and the entire filter package are sterilized.
Existing filter packages have an integral square package cover provided with a tab on each corner for tearing off the cover in order to expose the syringe connection. Manipulation of this known filter package to remove its cover is somewhat cumbersome and time-consuming. In order to open the filter package, the package housing must be firmly grasped with one hand, while the other hand seizes a tab and tears off the cover. To do this, the syringe must first be laid down, sometimes compromising sterility. In surgical and emergency activities, a quick and simple manipulation that maintains sterility is very important.
Punch-through bottles are known, which have a cover which can be penetrated by a cannula, in order to withdraw a fluid by means of a syringe. Such a cover, however, is not well-adapted to make the above manipulation easier, since this cover, in the same manner as the cover of the known filter package, must be removed before the withdrawal of a generally flat-shaped filter.
It is therefore an object of the present invention to an improved filter package that may be manipulated more simply and more rapidly and that does not compromise sterility.